1. Field of the Invention
The present invention relates to an outboard motor, and more particularly, it relates to an outboard motor including an engine and an engine holder.
2. Description of the Related Art
An outboard motor including an engine and an engine holder is known in general. Such an outboard motor is disclosed in Japanese Patent Laid-Open No. 2001-303920, for example.
Japanese Patent Laid-Open No. 2001-303920 discloses an outboard motor including an engine and an engine holder including an upper surface to which the engine is fixed. This engine includes a crank case including a crank shaft. Conceivably, this engine is arranged adjacent to the crank case in a horizontal direction and includes a cylinder body including a cylinder. In the case where the engine including the cylinder body and the crank case is bonded onto the engine holder, a three-surface bonding portion where boundary surfaces between the cylinder body, the crank case, and the engine holder intersect with each other is generated. The crank shaft is conceivably arranged substantially adjacent to the three-surface bonding portion.
In the outboard motor described in Japanese Patent Laid-Open No. 2001-303920, however, a very small clearance easily remains in the three-surface bonding portion where the boundary surfaces between the cylinder body, the crank case, and the engine holder intersect with each other even in the case where the boundary surfaces are sealed by gaskets. In the outboard motor described in Japanese Patent Laid-Open No. 2001-303920, an inner portion of the three-surface bonding portion is water resistant (seawater resistant) due to a supply of lubrication oil thereto, but an oil supply path is located in the three-surface bonding portion such that oil may leak. In the case where no oil is supplied to the three-surface bonding portion, on the other hand, components arranged in the cylinder body and the crank case are exposed to external water, and hence water resistant (seawater resistant) surface treatment must be performed on the components arranged in the cylinder body and the crank case.